| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2021 Facebook */ |
| #include "vmlinux.h" |
| #include <bpf/bpf_helpers.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_HASH); |
| __uint(max_entries, 3); |
| __type(key, __u32); |
| __type(value, __u64); |
| } hashmap SEC(".maps"); |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_PERCPU_HASH); |
| __uint(max_entries, 1); |
| __type(key, __u32); |
| __type(value, __u64); |
| } percpu_map SEC(".maps"); |
| |
| struct callback_ctx { |
| struct __sk_buff *ctx; |
| int input; |
| int output; |
| }; |
| |
| static __u64 |
| check_hash_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
| struct callback_ctx *data) |
| { |
| struct __sk_buff *skb = data->ctx; |
| __u32 k; |
| __u64 v; |
| |
| if (skb) { |
| k = *key; |
| v = *val; |
| if (skb->len == 10000 && k == 10 && v == 10) |
| data->output = 3; /* impossible path */ |
| else |
| data->output = 4; |
| } else { |
| data->output = data->input; |
| bpf_map_delete_elem(map, key); |
| } |
| |
| return 0; |
| } |
| |
| __u32 cpu = 0; |
| __u32 percpu_called = 0; |
| __u32 percpu_key = 0; |
| __u64 percpu_val = 0; |
| int percpu_output = 0; |
| |
| static __u64 |
| check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val, |
| struct callback_ctx *unused) |
| { |
| struct callback_ctx data; |
| |
| percpu_called++; |
| cpu = bpf_get_smp_processor_id(); |
| percpu_key = *key; |
| percpu_val = *val; |
| |
| data.ctx = 0; |
| data.input = 100; |
| data.output = 0; |
| bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0); |
| percpu_output = data.output; |
| |
| return 0; |
| } |
| |
| int hashmap_output = 0; |
| int hashmap_elems = 0; |
| int percpu_map_elems = 0; |
| |
| SEC("tc") |
| int test_pkt_access(struct __sk_buff *skb) |
| { |
| struct callback_ctx data; |
| |
| data.ctx = skb; |
| data.input = 10; |
| data.output = 0; |
| hashmap_elems = bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0); |
| hashmap_output = data.output; |
| |
| percpu_map_elems = bpf_for_each_map_elem(&percpu_map, check_percpu_elem, |
| (void *)0, 0); |
| return 0; |
| } |